/*
 * $Header: /home/jerenkrantz/tmp/commons/commons-convert/cvs/home/cvs/jakarta-commons//httpclient/src/java/org/apache/commons/httpclient/params/HttpParams.java,v 1.6 2004/05/13 04:01:22 mbecke Exp $
 * $Revision: 480424 $
 * $Date: 2006-11-29 06:56:49 +0100 (Wed, 29 Nov 2006) $
 *
 * ====================================================================
 *
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You under the Apache License, Version 2.0
 *  (the "License"); you may not use this file except in compliance with
 *  the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 *
 */

package org.apache.commons.httpclient.params;

/**
 * This interface represents a collection of HTTP protocol parameters. Protocol
 * parameters may be linked together to form a hierarchy. If a particular
 * parameter value has not been explicitly defined in the collection itself, its
 * value will be drawn from the parent collection of parameters.
 * 
 * @author <a href="mailto:oleg@ural.ru">Oleg Kalnichevski</a>
 * 
 * @version $Revision: 480424 $
 * 
 * @since 3.0
 */
public interface HttpParams {

	/**
	 * Returns the parent collection that this collection will defer to for a
	 * default value if a particular parameter is not explicitly set in the
	 * collection itself
	 * 
	 * @return the parent collection to defer to, if a particular parameter is
	 *         not explictly set in the collection itself.
	 * 
	 * @see #setDefaults(HttpParams)
	 */
	public HttpParams getDefaults();

	/**
	 * Assigns the parent collection that this collection will defer to for a
	 * default value if a particular parameter is not explicitly set in the
	 * collection itself
	 * 
	 * @param params
	 *            the parent collection to defer to, if a particular parameter
	 *            is not explictly set in the collection itself.
	 * 
	 * @see #getDefaults()
	 */
	public void setDefaults(final HttpParams params);

	/**
	 * Returns a parameter value with the given name. If the parameter is not
	 * explicitly defined in this collection, its value will be drawn from a
	 * higer level collection at which this parameter is defined. If the
	 * parameter is not explicitly set anywhere up the hierarchy, <tt>null</tt>
	 * value is returned.
	 * 
	 * @param name
	 *            the parent name.
	 * 
	 * @return an object that represents the value of the parameter.
	 * 
	 * @see #setParameter(String, Object)
	 */
	public Object getParameter(final String name);

	/**
	 * Assigns the value to the parameter with the given name
	 * 
	 * @param name
	 *            parameter name
	 * @param value
	 *            parameter value
	 */
	public void setParameter(final String name, final Object value);

	/**
	 * Returns a {@link Long} parameter value with the given name. If the
	 * parameter is not explicitly defined in this collection, its value will be
	 * drawn from a higer level collection at which this parameter is defined.
	 * If the parameter is not explicitly set anywhere up the hierarchy, the
	 * default value is returned.
	 * 
	 * @param name
	 *            the parent name.
	 * @param defaultValue
	 *            the default value.
	 * 
	 * @return a {@link Long} that represents the value of the parameter.
	 * 
	 * @see #setLongParameter(String, long)
	 */
	public long getLongParameter(final String name, long defaultValue);

	/**
	 * Assigns a {@link Long} to the parameter with the given name
	 * 
	 * @param name
	 *            parameter name
	 * @param value
	 *            parameter value
	 */
	public void setLongParameter(final String name, long value);

	/**
	 * Returns an {@link Integer} parameter value with the given name. If the
	 * parameter is not explicitly defined in this collection, its value will be
	 * drawn from a higer level collection at which this parameter is defined.
	 * If the parameter is not explicitly set anywhere up the hierarchy, the
	 * default value is returned.
	 * 
	 * @param name
	 *            the parent name.
	 * @param defaultValue
	 *            the default value.
	 * 
	 * @return a {@link Integer} that represents the value of the parameter.
	 * 
	 * @see #setIntParameter(String, int)
	 */
	public int getIntParameter(final String name, int defaultValue);

	/**
	 * Assigns an {@link Integer} to the parameter with the given name
	 * 
	 * @param name
	 *            parameter name
	 * @param value
	 *            parameter value
	 */
	public void setIntParameter(final String name, int value);

	/**
	 * Returns a {@link Double} parameter value with the given name. If the
	 * parameter is not explicitly defined in this collection, its value will be
	 * drawn from a higer level collection at which this parameter is defined.
	 * If the parameter is not explicitly set anywhere up the hierarchy, the
	 * default value is returned.
	 * 
	 * @param name
	 *            the parent name.
	 * @param defaultValue
	 *            the default value.
	 * 
	 * @return a {@link Double} that represents the value of the parameter.
	 * 
	 * @see #setDoubleParameter(String, double)
	 */
	public double getDoubleParameter(final String name, double defaultValue);

	/**
	 * Assigns a {@link Double} to the parameter with the given name
	 * 
	 * @param name
	 *            parameter name
	 * @param value
	 *            parameter value
	 */
	public void setDoubleParameter(final String name, double value);

	/**
	 * Returns a {@link Boolean} parameter value with the given name. If the
	 * parameter is not explicitly defined in this collection, its value will be
	 * drawn from a higer level collection at which this parameter is defined.
	 * If the parameter is not explicitly set anywhere up the hierarchy, the
	 * default value is returned.
	 * 
	 * @param name
	 *            the parent name.
	 * @param defaultValue
	 *            the default value.
	 * 
	 * @return a {@link Boolean} that represents the value of the parameter.
	 * 
	 * @see #setBooleanParameter(String, boolean)
	 */
	public boolean getBooleanParameter(final String name, boolean defaultValue);

	/**
	 * Assigns a {@link Boolean} to the parameter with the given name
	 * 
	 * @param name
	 *            parameter name
	 * @param value
	 *            parameter value
	 */
	public void setBooleanParameter(final String name, boolean value);

	/**
	 * Returns <tt>true</tt> if the parameter is set at any level,
	 * <tt>false</tt> otherwise.
	 * 
	 * @param name
	 *            parameter name
	 * 
	 * @return <tt>true</tt> if the parameter is set at any level,
	 *         <tt>false</tt> otherwise.
	 */
	public boolean isParameterSet(final String name);

	/**
	 * Returns <tt>true</tt> if the parameter is set locally, <tt>false</tt>
	 * otherwise.
	 * 
	 * @param name
	 *            parameter name
	 * 
	 * @return <tt>true</tt> if the parameter is set locally, <tt>false</tt>
	 *         otherwise.
	 */
	public boolean isParameterSetLocally(final String name);

	/**
	 * Returns <tt>true</tt> if the parameter is set and is <tt>true</tt>,
	 * <tt>false</tt> otherwise.
	 * 
	 * @param name
	 *            parameter name
	 * 
	 * @return <tt>true</tt> if the parameter is set and is <tt>true</tt>,
	 *         <tt>false</tt> otherwise.
	 */
	public boolean isParameterTrue(final String name);

	/**
	 * Returns <tt>true</tt> if the parameter is either not set or is
	 * <tt>false</tt>, <tt>false</tt> otherwise.
	 * 
	 * @param name
	 *            parameter name
	 * 
	 * @return <tt>true</tt> if the parameter is either not set or is
	 *         <tt>false</tt>, <tt>false</tt> otherwise.
	 */
	public boolean isParameterFalse(final String name);

}
